A name given to a system of adding harmonies to the diatonic scale, using it as the lowest part. From the nature and relation of the chords added, many laws as to progression and modulation were deduced; in fact it was formerly taught as a formula for the assistance of students, who committed to memory the harmony or harmonies which each degree was capable of bearing. [Stainer, John; Barrett, W.A.; A Dictionary of Musical Terms; Novello, Ewer and Co., London, pre-1900]